As is generally known in the art, a conventional air conditioner employs evaporation heat which a refrigerant absorbs from surroundings when it evaporates. Typically, as the refrigerant, liquids such as ammonia, Freon, an azeotropic refrigerant mixture, chloromethyl, or the like, are used.
In the conventional air conditioner, as a vaporized refrigerant compressed by a compressor at high pressure passes through a condenser, the refrigerant exchanges heat with outside air and condenses to a liquid refrigerant at high pressure. The liquid refrigerant at high pressure is then turned into a low pressure liquid refrigerant after passing through an expansion valve, a capillary tube, or the like. Thereupon, the low pressure liquid refrigerant enters an evaporator, exchanges heat with inside air, and evaporates. Next, the evaporated low pressure refrigerant enters the compressor to complete an air conditioning cycle which is continuously repeated. The air cooled by the evaporation heat absorbed by the refrigerant in the evaporator is directed by a blower fan into a space or toward a target object to perform a cooling function.
Therefore, the conventional air conditioner uses a refrigerant the phase of which can be easily changed, that is, can be easily condensed and evaporated, to cool the space or target object.
Generally, in the case of a base communication station or a communication-equipped car, various wired or wireless communication equipment is installed. This communication equipment is likely to have loose connections or to break down due to constant generation of heat, whereby malfunction of the communication equipment may result. For this reason, it is necessary to cool the communication equipment all year round to minimize malfunction of the communication equipment due to heat generated therein.
However, in the conventional air conditioner for communication equipment, since naturally cold outside temperatures are not appropriately used and the air conditioner is only driven through the use of electric power, electric power consumption is increased.
Also, the refrigerants used in the conventional air conditioner for communication equipment are expensive and have been found to cause environmental pollution.
In consideration of these facts, in an effort to solve the above-described problems, the present applicant has disclosed Korean Patent Application No. 2002-41905 entitled “Multi-use air conditioner and control method thereof”.
Nevertheless, in this type of air conditioner, if one of the component elements breaks down, because the operation of the entire air conditioner is interrupted, the space cannot be maintained in a cooled state for the time during which the operation of the communication equipment is interrupted.